Motor

ABSTRACT

A motor according to the present invention includes: a stator having a stator core and a coil; a rotor having a rotary shaft and a rotation body; a shaft bearing rotatably supporting the rotor; and a molding resin covering the stator. The motor has a coil end that is the coil protruding from the stator core in a shaft center X direction, and has a non-combustible layer provided to cover the coil end. The non-combustible layer is a metallic cover made of, for example, metal. The metallic cover is disposed to cover a periphery of a coil assembly in which the coil is formed on the stator core through an insulator. The metallic cover is integrated with the coil assembly by a molding resin.

TECHNICAL FIELD

The present invention relates to a motor whose stator is covered withmolding resin.

BACKGROUND ART

FIG. 41 is a cross-sectional view showing a configuration example ofconventional motor 900. As shown in FIG. 41, motor 900 includes rotor920 and stator 910, where stator 910 is covered with molding resin 931;and a motor having this configuration is also referred to as moldedmotor and already well-known (for example, PTL 1).

As shown in FIG. 41, stator 910 has: stator core 911 made of a pluralityof metallic sheets; and coil 912 made of a winding wire wound on statorcore 911. Coil 912 provided on stator 910 is covered with molding resin931. In particular, a part protruding from stator core 911 of coil 912as shown in FIG. 41 is also referred to as coil end 912 a. Between coil912 and stator core 911, there is attached insulator 913 for the purposeof electric insulation between coil 912 and stator core 911.

Incidentally, when an excessive current flows through coil 912, coil 912generates heat and heats up to extremely high temperatures, and there isa possibility of causing a layer short. For this reason, an outerperiphery of a conductor of the winding wire constituting coil 912 iscovered with insulating material. However, when coil 912 generates heat,the insulating material of the winding wire whose outer periphery isinsulated with the insulating material may be melted, and for thisreason or other reasons, conductors can be short circuited. In a casewhere a layer short has occurred in coil 912 under an unusualenvironment where any safety protection device cannot work at all, aspark sometimes occurs. When a spark due to a layer short has occurred,a gas may be generated due to insulator 913 or the like heated by thespark, and the gas can be ignited by the spark and can generate flame.

On the other hand, on a part where coil 912 is in contact with moldingresin 931 or other parts, applied heat and the like sometimes causedeterioration of physical properties of molding resin 931. When thephysical properties of molding resin 931 has been deteriorated, a crackor the like will be generated in molding resin 931.

As a result, if a layer short has occurred while a crack or the like isgenerated in molding resin 931, gas generated from insulator 913 or thelike is sometimes ignited to generate fire, and the generated fire canleak out of motor 900 through a part of molding resin 931 having thecrack or the like.

In this case, the possibility of fire or smoke leaking outside isextremely low since all part but coil end 912 a of coil 912 issurrounded by stator core 911. However, because coil end 912 a protrudesfrom stator core 911, coil end 912 a is in contact with molding resin931. Therefore, there is a possibility that flame is generated on apart, of molding resin 931, being in contact with coil end 912 a andthat fire or smoke leaks outside.

In the above-described motor and in a device in which the motor isprovided (the device is also referred to as motored device), in order toprevent fire or smoke from leaking out due to an excessive currentflowing through the coil as described above, a safe protection circuitfor preventing an excessive current from flowing through the coil of thestator is provided inside motors (for example, on a control boardprovided inside a motor) or in motored devices.

CITATION LIST Patent Literature

PTL 1: PCT International Publication No. WO 2012/101976

SUMMARY OF THE INVENTION

A motor of the present invention includes a stator and a rotor. Thestator has a stator core and a coil wound on the stator core. The rotoris located on an inner side of the stator and has: a rotary shaftextending in a shaft center direction; and a rotation body that containsa magnet component, extends in a shaft center direction, and is fixed tothe rotary shaft. The motor further includes: a shaft bearing rotatablysupporting the rotor; and a molding resin covering the stator. The coilhas a coil end protruding in the shaft center direction from the statorcore, and the motor includes a non-combustible layer provided to coverthe coil end.

With this configuration, since the non-combustible layer is provided tocover the coil end of the coil the stator, even if by any chance a safeprotection circuit for preventing an excessive current from flowingthrough the coil of the stator does not normally function and anexcessive current flows through the coil of the stator to cause a layershort, fire caused by the insulator or the like is blocked by thenon-combustible layer, and fire and smoke can be prevented from comingoutside of the motor.

Further, in a motor of the present invention, at least a part of thenon-combustible layer is formed to extend in the shaft center directionat a position on an outer peripheral side of the coil end.

With this configuration, if fire is about to spread to the outerperipheral side of the coil end, the fire is blocked by thenon-combustible layer. The non-combustible layer may be formed on theouter surface of the molding resin.

Further, in the motor of the present invention, at least a part of thenon-combustible layer is formed to extend, in a radial direction, at aposition on the side of the coil end opposite to the stator core.

With this configuration, even if fire is about to spread to the side ofthe coil end opposite to the stator core, in other words, to the outerside in the shaft center direction, the fire is blocked by thenon-combustible layer. The non-combustible layer may be formed on theouter surface of the molding resin.

Further, the non-combustible layer of the motor of the present inventionmay be formed to cover the coil end from a position on the outerperipheral side of the coil end, from a position on the side of the coilend opposite to the stator core, and from a position on the innerperipheral side of the coil end.

With this configuration, fire is blocked by the non-combustible layer,even if the fire is about to spread in any direction to the followingpositions: the position on the outer peripheral side of the coil end;the position on the side of the coil end opposite to the stator core;and the position on the inner peripheral side of the coil end.

The non-combustible layer may be formed of air or may be formed of anon-combustible material such as inorganic material such as metal orceramic. It is preferable that a metallic cover be further provided tocover the coil end through the molding resin.

The non-combustible layer of the motor of the present invention maycover a transition wire for the coil in addition to the coil end. Theconductive wire constituting the coil of the stator can break in somecases. If by any chance a safe protection circuit for preventing anexcessive current from flowing through the coil of the stator does notnormally function and an excessive current flows through a conductivewire constituting the coil of the stator (for example, the transitionwire), the conductive wire sparks and generates a spark at the time ofwire break. In this case, there will be a possibility that a gasgenerated from the insulator or the like can be ignited by the spark andcan generate flame. However, also in this case, since thenon-combustible layer covers the transition wire for the coil, the firegenerated from the transition wire at the time of wire break is blockedby the non-combustible layer.

As described above, the present invention is provided with anon-combustible layer covering the coil end protruding in the shaftcenter direction from the stator core. Owing to the above arrangement,even if by any chance a safe protection circuit for preventing anexcessive current from flowing through the coil of the stator does notnormally function and an excessive current flows through the coil of thestator to cause a layer short, the fire caused by the insulator or thelike is blocked by the non-combustible layer, with the presentinvention. Therefore, fire and smoke can be prevented from comingoutside of the motor. As a result, reliability and safety as a motor isfurther improved. Further, if a metallic cover is further provided tocover the coil end through the molding resin, it is possible to moresurely prevent fire and smoke from coming outside of the motor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a half cross-sectional view of a motor according to a firstexemplary embodiment of the present invention.

FIG. 2 is a plan cross-sectional view of the motor according to thefirst exemplary embodiment of the present invention taken along line 2-2in FIG. 1.

FIG. 3 is a plan cross-sectional view of the motor according to thefirst exemplary embodiment of the present invention taken along line 3-3in FIG. 1.

FIG. 4 is an exploded perspective view of the motor according to thefirst exemplary embodiment of the present invention.

FIG. 5 is an enlarged half cross-sectional view of a main part of themotor according to the first exemplary embodiment of the presentinvention.

FIG. 6 is a half cross-sectional view of a modified example of the motorof the first exemplary embodiment.

FIG. 7 is a half cross-sectional view of a motor according to a secondexemplary embodiment of the present invention.

FIG. 8 is a half cross-sectional view of a motor according to a thirdexemplary embodiment of the present invention.

FIG. 9 is a half cross-sectional view of a motor according to a fourthexemplary embodiment of the present invention.

FIG. 10 is an enlarged half cross-sectional view of a main part of themotor according to the fourth exemplary embodiment of the presentinvention.

FIG. 11 is a half cross-sectional view of a modified example of themotor according to the fourth exemplary embodiment of the presentinvention.

FIG. 12 is a half cross-sectional view of a motor according to a fifthexemplary embodiment of the present invention.

FIG. 13 is a half cross-sectional view of a modified example of themotor according to the fifth exemplary embodiment of the presentinvention.

FIG. 14 is a half cross-sectional view of another modified example ofthe motor according to the fifth exemplary embodiment of the presentinvention.

FIG. 15 is a half cross-sectional view of still another modified exampleof the motor according to the fifth exemplary embodiment of the presentinvention.

FIG. 16 is an exploded perspective view of a motor according to a sixthexemplary embodiment of the present invention.

FIG. 17 is a cross-sectional view of the motor according to the sixthexemplary embodiment of the present invention.

FIG. 18 is a plan cross-sectional view of the motor according to thesixth exemplary embodiment of the present invention taken along line18-18 in FIG. 17.

FIG. 19 is an external perspective view of the motor according to thesixth exemplary embodiment of the present invention.

FIG. 20 is an exploded perspective view of another motor according tothe sixth exemplary embodiment of the present invention.

FIG. 21 is a cross-sectional view showing a cross-section of a metallicinner cover of the motor according to the sixth exemplary embodiment ofthe present invention and showing a cross-section of a tooth on which acoil is wound.

FIG. 22 is an exploded perspective view of a coil assembly and ametallic inner cover of the motor according to the sixth exemplaryembodiment of the present invention.

FIG. 23 is a configuration diagram of the metallic inner cover disposedon an outer periphery of the coil assembly of the motor according to thesixth exemplary embodiment of the present invention.

FIG. 24 is a diagram for illustrating the metallic outer cover of themotor according to the sixth exemplary embodiment of the presentinvention.

FIG. 25 is a cross-sectional view of a motor according to a seventhexemplary embodiment of the present invention.

FIG. 26 is a perspective view of a metallic inner cover of the motoraccording to the seventh exemplary embodiment of the present invention.

FIG. 27 is a cross-sectional view of the metallic inner cover and a coilassembly of the motor according to the seventh exemplary embodiment ofthe present invention.

FIG. 28 is a cross-sectional view of a motor according to an eighthexemplary embodiment of the present invention.

FIG. 29 is an enlarged cross-sectional view of the vicinity of a notchin the motor according to the eighth exemplary embodiment of the presentinvention.

FIG. 30 is a plan cross-sectional view of the motor according to theeighth exemplary embodiment of the present invention taken along line30-30 in FIG. 29.

FIG. 31 is an enlarged cross-sectional view of the vicinity of anothernotch in the motor according to the eighth exemplary embodiment of thepresent invention.

FIG. 32 is a cross-sectional view of a motor according to a ninthexemplary embodiment of the present invention.

FIG. 33 is an enlarged view of the vicinity of a metallic outer cover inthe motor according to the ninth exemplary embodiment of the presentinvention.

FIG. 34 is a partial cross-sectional view of a modified example of themotor according to the ninth exemplary embodiment of the presentinvention.

FIG. 35 is a plan cross-sectional view of a coil assembly of a motor ofa tenth exemplary embodiment of the present invention, where a metallicinner cover is fit in the coil assembly but a swaging process is notperformed yet.

FIG. 36 is an enlarged cross-sectional view of area AA in FIG. 35 in themotor according to the tenth exemplary embodiment of the presentinvention.

FIG. 37 is a perspective view showing an outer appearance of the coilassembly of the motor according to the tenth exemplary embodiment of thepresent invention.

FIG. 38 is a cross-sectional view of a motor according to an eleventhexemplary embodiment of the present invention.

FIG. 39 is an exploded perspective view of a terminal cap, a metallicinner cover, and a coil assembly in the motor according to the eleventhexemplary embodiment of the present invention.

FIG. 40 is a partially enlarged cross-sectional view of a motoraccording to a twelfth exemplary embodiment of the present invention.

FIG. 41 is a front cross-sectional view of a conventional motor.

DESCRIPTION OF EMBODIMENTS

In a motor in each exemplary embodiment of the present invention, aconfiguration to be described later can more surely prevent fire andsmoke from coming outside of the motor.

That is to say, a safe protection circuit to deal with overcurrent isconventionally provided as described above; however, in a case where byany chance none of safe protection circuits functions normally, anexcessive current can flow through the coil of the stator. For thisreason, in order to improve tolerance of motored devices, a motor thatis a constituent element of motored devices needs to be safer.Specifically, there is an issue that it is required to prevent fire fromleaking from a motor to the outside of the motor even if a layer shorthas occurred in the coil under the above-mentioned unusual environment.

To address the issue, in the present exemplary embodiment, in a motormolded with a molding resin, there is provided a non-combustible layercovering at least a coil end. The present exemplary embodiment can moresurely prevent fire and smoke from coming outside of a motor.

Hereinafter, exemplary embodiments of the present invention will bedescribed with reference to the drawings. Note that, in the followingdescription, the same components are assigned the same reference marks,and corresponding descriptions are used.

First Exemplary Embodiment

FIG. 1 is a half cross-sectional view of motor 101 according to a firstexemplary embodiment of the present invention. FIG. 2 is a plancross-sectional view of motor 101 according to the first exemplaryembodiment of the present invention taken along line 2-2 in FIG. 1. FIG.3 is a plan cross-sectional view of motor 101 according to the firstexemplary embodiment of the present invention taken along line 3-3 inFIG. 1. FIG. 4 is an exploded perspective view of motor 101 according tothe first exemplary embodiment of the present invention. FIG. 5 is anenlarged half cross-sectional view of a main part of motor 101 accordingto the first exemplary embodiment of the present invention.

As shown in FIGS. 1 to 5, motor 101 includes stator 10, rotor 20 locatedinside stator 10, a pair of shaft bearings 30A, 30B, and molding resin31 covering stator 10. Rotor 20 has rotary shaft 21 disposed at a centerof rotor 20. Rotor 20 are rotatably supported with both sides of rotaryshaft 21 being held by the pair of shaft bearings 30A, 30B. Note thatillustrated motor 101 is a brushless motor. In addition, in the presentexemplary embodiment, motor 101 is also provided with: first and secondbrackets 32 and 33 constituting an outer shell (chassis) of motor 101;and circuit board 34. First and second brackets 32, 33 are made of metaland have an approximately disk shape in a plan view

Stator 10 has: stator core 11 configured with a plurality of metallicsheets being laminated; and coils 12 wound on stator core 11. As shownin FIGS. 2 and 3, stator core 11 has: yoke 11 a formed to surround rotor20 disposed along shaft center X of rotary shaft 21; and a plurality ofteeth lib protruding in a protruding shape from yoke 11 a toward shaftcenter X.

In the following description, the words “teeth” (plural form of tooth)and “tooth” are separately used. Specifically, a plurality of teethprotruding in a central direction of a stator core having a circularring-shape are written as teeth (plural form of tooth). One of theplurality of teeth of the stator core is written as tooth.

Shaft center X is also referred to as shaft direction X.

As shown in FIGS. 1 and 4, rotor 20 has: rotary shaft 21 extending in ashaft center X direction; and rotation body 22 that includes a magnetcomponent, extends in the shaft center X direction, and is fixed torotary shaft 21. Rotation body 22 is configured, for example, with aplurality of magnets 24, which are permanent magnets, assembled on anouter peripheral surface of rotor core 23 such that polarities ofadjacent magnets 24 are alternately arranged. Rotary shaft 21 of rotor20 is rotatably supported by shaft bearing 30A fit in a central part offirst bracket 32 and by shaft bearing 30B fit in a central part ofsecond bracket 33, whereby rotor 20 is rotatably supported.

As shown in FIG. 5, coil 12 is wound on stator core 11 via insulators 13made of insulating material such as resin. Schematically, insulators 13each have bottom surface part 13 a, outer peripheral wall 13 b, andinner peripheral wall 13 c.

Bottom surface parts 13 a of insulators 13 are each mounted on an endsurface of stator core 11 or the like. In the present exemplaryembodiment, bottom surface part 13 a of each insulator 13 is formed of aplane extending in a direction that intersects with shaft center X.Outer peripheral wall 13 b of each insulator 13 is vertically providedon the outer peripheral side of a part on which coil 12 is wound, andouter peripheral wall 13 b restricts the coil position. In the presentexemplary embodiment, outer peripheral wall 13 b of each insulator 13 isformed of a wall surface extending in a direction along shaft center X.Inner peripheral wall 13 c of each insulator 13 is vertically providedon an inner peripheral side of a part on which coil 12 is wound, andinner peripheral wall 13 c restricts the coil position. Inner peripheralwall 13 c of each insulator 13 is formed of a wall surface extending ina direction along shaft center X. Inner peripheral wall 13 c of eachinsulator 13 is located closer to shaft center X than outer peripheralwall 13 b is. As long as insulator 13 insulates between coil 12 andstator core 11, a shape of insulator 13 is not limited to theabove-described shape.

Coil 12 has coil ends 12 a each protruding in the shaft center Xdirection from stator core 11. With respect to FIGS. 1 and 5, coil ends12 a each stick out and protrude from stator core 11 upward and downwardon the diagram. As shown in FIGS. 2 and 3, a part of each coil 12 otherthan coil ends 12 a is included in stator core 11. Coils 12, insulators13, and stator core 11 of stator 10 except an inner peripheral surfaceof each tooth lib are covered with molding resin 31. An outer peripheralsurface side part of molding resin 31 is formed in a cylindrical shapeand constitutes barrel (case barrel) 31 a, which is a part of an outershell (chassis) of motor 101. End edges of barrel 31 a are each insertedin an outer circumferential part of each of first and second brackets 32and 33, thereby being fixed. As shown in FIG. 1, in the presentexemplary embodiment, circuit board 34 is mounted on a part of asection, of molding resin 31, covering coils 12. Electronic component 34a constituting a connection circuit to coils 12, various controlcircuits, and a safe protection circuit are mounted on circuit board 34.

Motor 101 is provided with non-combustible layers 41A, 41B, 42A, 42B, 43that cover coil ends 12 a. In the present exemplary embodiment, as shownin FIGS. 1 and 5, non-combustible layers 41A, 41B, 42A, 42B, 43constituted by air in a space part are provided to cover coil end molds31 b of molding resin 31 from outside, where coil end molds 31 b covercoil ends 12 a.

In more detail, groove-shaped recesses are each formed in a part betweeneach coil end mold 31 b and barrel 31 a, and non-combustible layers 41A,41B serving as groove parts are each formed of air in each of spaces ofthe groove-shaped recesses. These non-combustible layers 41A, 41B are atpositions in molding resin 31 on the outer peripheral side of coil ends12 a and each extend to cover a dimension range corresponding to eachcoil end 12 a in the shaft center X direction. In other words, in thepresent exemplary embodiment, non-combustible layers 41A, 41B are formedsuch that dimension h1, of each of non-combustible layers 41A and 41B,in the shaft center X direction is longer than dimension h3 along whichan attaching part of coil end mold 31 b and insulator 13 to an end faceof stator core 11 is provided in the shaft center X direction.

In other words, as shown in FIG. 5, non-combustible layers 41A and 41Bserving as grooves are located on the outer peripheral side of coil ends12 a in a direction intersecting with shaft center X, in other words, ina radial direction (the direction indicated by arrow Y in the drawing,which is hereinafter written as “radial direction Y”). In other words,in the radial direction Y, non-combustible layers 41A, 41B are eachlocated between coil end 12 a and molding resin 31. In addition, in theshaft center X direction, heights h1 of non-combustible layers 41A, 41Bare greater than height h2 of coil ends 12 a.

Further, on the side where circuit board 34 is mounted, spaces are eachformed also between coil end mold 31 b except a part on which circuitboard 34 is mounted and circuit board 34 and between coil end mold 31 band first bracket 32, and air in the respective spaces formsnon-combustible layers 42A, 42B. In addition, also between secondbracket 33 and one of coil end molds 31 b that is close to secondbracket 33, there is formed a space, and air in the space formsnon-combustible layer 43.

These non-combustible layers 42A, 42B, 43 are formed to extend in theradial direction Y, on the side of each coil end 12 a opposite to statorcore 11, in other words, at the positions on the outer side in the shaftcenter direction. In addition, in present exemplary embodiment,non-combustible layers 42A, 42B, 43 formed of space are provided in adimension range in the radial direction Y in which each coil end mold 31b is provided.

In other words, as shown in FIG. 5, in the direction along shaft centerX, non-combustible layers 42A, 42B are located in the direction, withrespect to coil end 12 a, opposite to the direction in which stator core11 is located. In the direction intersecting with shaft center X, inother words, in the radial direction Y, width W1 of the spaces formed bynon-combustible layers 42A, 42B is wider than width W2 of coil end 12 a.

In the direction along shaft center X, non-combustible layer 43 islocated in the direction, with respect to coil end 12 a, opposite to thedirection in which stator core 11 is located. In the directionintersecting with shaft center X, in other words, in the radialdirection Y, width W3 of a space formed by non-combustible layer 43 iswider than width W2 of coil end 12 a.

The above configuration provides the following actions and effects. Ifby any chance a safe protection circuit configured to prevent anexcessive current from flowing through coil 12 of stator 10 does notnormally function, an excessive current will flow through coil 12 ofstator 10. In that case, coil 12 generates heat and heats up toextremely high temperatures, whereby a layer short occurs. If a layershort has occurred in coil 12, a spark will occur. There is apossibility that gas generated from insulator 13 or the like can beignited by the spark having occurred and can thus generate flame. Toaddress such a problem, in the present exemplary embodiment,non-combustible layers 41A, 41B, 42A, 42B, 43 are provided to cover coilend molds 31 b that cover coil ends 12 a. Thus, even if a layer shorthas occurred, fire due to insulator 13 and the like is blocked bynon-combustible layers 41A, 41B, 42A, 42B, 43, so that fire and smokecan be prevented from coming outside of motor 101.

Specifically, suppose, for example, the case where fire is caused fromcoil end 12 a and the fire is about to spread to the outer peripheralside, in the radial direction Y, of coil end mold 31 b covering coil end12 a and insulator 13. To address this case, in the present exemplaryembodiment, non-combustible layers 41A, 41B are provided to be formed toextend in the shaft center X direction at the positions on the outerperipheral sides of coil ends 12 a. Thus, even if the fire is about tospread as described above, the fire and smoke are blocked bynon-combustible layers 41A, 41B and do not easily leak out of motor 101.

In addition, suppose, for example, the case where fire is caused fromcoil end 12 a and the fire is about to spread to the side, of coil endmold 31 b covering coil end 12 a and insulator 13, opposite to statorcore 11 in the shaft center X direction. To address this case, in thepresent exemplary embodiment, non-combustible layers 42A, 42B, 43 areeach provided to be formed to extend in the radial direction Y on theside of coil end 12 a opposite to stator core 11. Thus, even if the fireis about to spread as described above, the fire and smoke are blocked bynon-combustible layers 42A, 42B, 43 and do not easily leak out of motor101.

In the present exemplary embodiment, the drawings show the case wherenon-combustible layers 41A, 41B formed to extend in the shaft center Xdirection at positions on the outer peripheral side of coil ends 12 a inthe radial direction Y are formed parallel to the shaft center Xdirection. However, the non-combustible layers are not limited to theabove example, and the non-combustible layers only have to be connectedto each other on at least a part of each non-combustible layer in theshaft center X direction even if the distance from shaft center Xvaries. In addition, the drawings show the case where non-combustiblelayers 42A, 42B, 43 formed to extend in the radial direction Y on theside opposite to stator core 11 (outer side in the shaft center Xdirection) are formed almost along the radial direction Y. However, thenon-combustible layers are not limited to the above example, and thenon-combustible layers only have to be connected to each other on atleast a part of each non-combustible layer in radial direction Y even ifthe position in the shaft center X direction varies.

In the present exemplary embodiment, first bracket 32 is furtherprovided on the outside, of non-combustible layer 42A, in the shaftcenter X direction, in other words, on the side of coil end 12 aopposite to stator core 11. Thus, first bracket 32 further functions asa metallic cover covering coil end 12 a and surely prevents fire andsmoke from coming outside of motor 101, whereby reliability can beimproved.

The above exemplary embodiment describes the case where each ofnon-combustible layers 41A, 41B formed to extend in the shaft center Xdirection at the position on the outer peripheral side, of coil end 12a, in the radial direction Y is extended longer than dimension h3 alongwhich an attaching part of coil end mold 31 b and insulator 13 to an endface of stator core 11 is provided in the shaft center X direction.However, the non-combustible layers are not limited to the above exampleand may be made in another configuration, for example, as shown in FIG.6. FIG. 6 is a half cross-sectional view of a modified example of thepresent exemplary embodiment. Specifically, as shown in FIG. 6,regarding motor 101 a, non-combustible layers 41C, 41D are each formedto cut into the outer peripheral side of stator core 11 deeper thandimension h3 along which an attaching part of coil end mold 31 b andinsulator 13 to an end face of stator core 11 is provided in the shaftcenter X direction. With the above arrangement, if by any chance thesafe protection circuit does not normally function and fire has ignitedcoil end mold 31 b or insulator 13 from a part in the vicinity of coilend 12 a or the like, it is possible to more surely prevent fire fromcoming outside of motor 101 and motor 101 a, whereby reliability can beimproved.

Second Exemplary Embodiment

FIG. 7 is a half cross-sectional view of motor 102 according to a secondexemplary embodiment of the present invention.

The above first exemplary embodiment describes the case wherenon-combustible layers 41A, 41B, 41C, 41D, 42A, 42B, 43 are constitutedby air; however, the non-combustible layers are not limited to the firstexemplary embodiment, and the non-combustible layers may be formed of anon-combustible material. Specifically, in the present exemplaryembodiment, motor 102 including non-combustible layers 44, 45 made ofmetal will be described.

As shown in FIG. 7, non-combustible layers 44, 45 are formed of anon-combustible material made of metal. In addition, in the presentexemplary embodiment, coil end molds 31 b are covered withnon-combustible layers 44, 45 made of metal from outside of moldingresin 31. Specifically, non-combustible layer 44 is formed to extend ina shaft center X direction at a position on an outer peripheral surfaceof barrel 31 a of molding resin 31 and on the outer peripheral side ofcoil end 12 a close to circuit board 34. In other words, non-combustiblelayer 44 is formed to include coil end mold 31 b in the shaft center Xdirection.

In other words, non-combustible layer 44 is located on the outerperipheral side of coil end 12 a in a direction intersecting with ashaft center X, in other words, in the radial direction Y. Further,height h11 of non-combustible layer 44 is greater than height h2 of coilend 12 a in the shaft center X direction.

Further, non-combustible layer 45 extends from the outer peripheralsurface of barrel 31 a of molding resin 31 to the vicinity of shaftbearing 30B. More specifically, non-combustible layer 45 is formed toextend in the shaft center X direction at a position on the outerperipheral side of coil end 12 a close to second bracket 33 and on theouter peripheral surface of barrel 31 a of molding resin 31, and isformed to include coil end mold 31 b in the shaft center X direction. Inaddition, non-combustible layer 45 extends also in the radial directionY at a position on the side of coil end 12 a opposite to stator core 11and is formed to include coil end mold 31 b in the radial direction Y.

In other words, non-combustible layer 45 is formed to cover coil end 12a in a range from end part 45 a located in the direction along shaftcenter X to end part 45 b located in the radial direction Y.Specifically, in the direction along shaft center X, height h12 ofnon-combustible layer 45 is greater than height h2 of coil end 12 a.Further, in the radial direction Y, non-combustible layer 45 has widthW31 greater than width W2 of coil end 12 a.

If by any chance a safe protection circuit configured to prevent anexcessive current from flowing through coil 12 of stator 10 does notnormally function as described above, an excessive current will flowthrough coil 12 of stator 10. In that case, coil 12 generates heat andheats up to extremely high temperatures, whereby a layer short occurs.If a layer short has occurred in coil 12, a spark will occur. There is apossibility that gas generated from insulator 13 or the like can beignited by the spark having occurred and can thus generate flame. Toaddress such a problem, in the present exemplary embodiment,non-combustible layers 44 and 45 formed of a non-combustible materialmade of metal are provided. As a result, even if the fire is about tospread to the outer peripheral side of motor 102, the fire andaccompanying smoke are blocked by non-combustible layers 44, 45, wherebyfire and smoke can be prevented from coming outside of motor 102.

For example, if fire is caused from coil end 12 a and the fire is aboutto spread from coil end mold 31 b to the side opposite to stator core 11in the shaft center X direction, the fire and smoke are blocked bynon-combustible layer 45 and non-combustible layers 42A, 42B, 44,whereby fire and smoke can be prevented from coming outside of motor102.

For above-described non-combustible layers 44, 45 made of metal, it ispossible to use metallic material such as, iron, stainless steel, brass,or aluminum.

In particular, when iron or brass is used, it is possible to improve arustproof function by subjecting the surface to plating working.Specifically, when iron is used, it is possible to use a hot-dipgalvanized steel sheet (Japanese industrial standard (JIS): SGCD) or anelectrogalvanized steel sheet (JIS: SECD).

The present exemplary embodiment describes the case wherenon-combustible layers 44, 45 are formed of a non-combustible materialmade of metal; however, the material is not limited to metal, and aninorganic material such as ceramic or a molded article of aluminumhydroxide may be used instead of metal.

Third Exemplary Embodiment

FIG. 8 is a half cross-sectional view of motor 103 according to a thirdexemplary embodiment of the present invention.

In the present exemplary embodiment, as shown in FIG. 8, in a similarway to the first exemplary embodiment, there are providednon-combustible layers 41A, 41B each of which is made of air in a spaceformed to extend in the shaft center X direction at a position on theouter peripheral side, of coil end 12 a, in the radial direction Y. Inaddition to non-combustible layers 41A and 41B, metallic covers arefurther provided outside of molding resin 31. Specifically, in thepresent exemplary embodiment, a part, of each of first and secondbrackets 32, 33, along barrel 31 a of molding resin 31 is extended, anda function as a non-combustible layer is added to each of metallic coverunits 46, 47, which are the extended parts of first and second bracket32 and 33.

This configuration can more surely prevent fire and smoke from comingoutside of motor 103, thereby improving reliability. Although metalliccover units 46, 47 are made by extending first and second brackets 32,33 in the present exemplary embodiment, this configuration does notlimit the invention, and individual metallic covers may be provided asnon-combustible layer 44 of FIG. 7.

Fourth Exemplary Embodiment

FIG. 9 is a half cross-sectional view of motor 104 according to a fourthexemplary embodiment of the present invention. FIG. 10 is an enlargedhalf cross-sectional view of a main part of motor 104 according to thefourth exemplary embodiment of the present invention.

In the present exemplary embodiment, coil ends 12 a and insulators 13holding these coil ends 12 a are covered with non-combustible layers 50and 51 as shown in FIG. 9. Non-combustible layers 50 and 51 may be madeof air and are preferably made of a non-combustible material such as aninorganic material such as metal or ceramic. Alternatively, a spacebetween each of non-combustible layers 50 and 51 and corresponding coilend 12 a may be filled with air or molding resin 31.

FIGS. 9 and 10 show an example in which non-combustible layers 50, 51are configured of metal in a cap shape. Non-combustible layers 50, 51are each formed to surround coil end 12 a and insulator 13 holding coilend 12 a. More specifically, as shown in FIG. 10, non-combustible layer50 is configured with: outer peripheral enclosure 50 a at a position onthe outer peripheral side of outer peripheral wall 13 b of insulator 13;side enclosure 50 b at a position on the side of insulator 13 oppositeto a stator core; and inner peripheral enclosure 50 c at a position onan inner peripheral side of inner peripheral wall 13 c of insulator 13.Similarly, non-combustible layer 51 is configured with outer peripheralenclosure 51 a, side enclosure 51 b, and inner peripheral enclosure 51c.

In other words, in the radial direction Y, non-combustible layers 50, 51respectively have outer peripheral enclosures 50 a, 51 a and innerperipheral enclosures 50 c, 51 c. In the radial direction Y, outerperipheral enclosures 50 a, 51 a are each located on the outerperipheral side of outer peripheral wall 13 b of insulator 13. In theradial direction Y, inner peripheral enclosures 50 c, 51 c are eachlocated closer to shaft center X than inner peripheral wall 13 c ofinsulator 13 is.

In the direction along shaft center X, non-combustible layers 50, 51respectively have side enclosures 50 b, 51 b. In the direction alongshaft center X, side enclosures 50 b, 51 b are each located to face eachbottom surface part 13 a through coil end 12 a.

If by any chance a safe protection circuit configured to prevent anexcessive current from flowing through coil 12 of stator 10 does notnormally function as described above, an excessive current will flowthrough coil 12 of stator 10. In that case, coil 12 generates heat andheats up to extremely high temperatures, whereby a layer short occurs.If a layer short has occurred in coil 12, a spark will occur. There is apossibility that gas generated from insulator 13 or the like can beignited by the spark having occurred and can thus generate flame. Toaddress such a problem, in the present exemplary embodiment,non-combustible layers 50, 51 are each provided to cover coil end 12 aof coil 12 of stator 10 and insulator 13. Thus, even if a layer shorthas occurred in coil 12, fire due to insulator 13 and the like isblocked by non-combustible layers 50, 51, so that fire and smoke can beprevented from coming outside of motor 104.

Non-combustible layers 50, 51 respectively have outer peripheralenclosures 50 a, 51 a each formed to extend in the shaft center Xdirection at a position on an outer peripheral side of coil end 12 a andouter peripheral wall 13 b of insulator 13. Thus, for example, if fireis caused from coil end 12 a and is about to spread to the outerperipheral side, of coil end 12 a and insulator 13, in the radialdirection Y, the fire and smoke are blocked by outer peripheralenclosures 50 a, 51 a, and fire and smoke can be prevented from comingoutside of motor 104.

Further, non-combustible layers 50, 51 respectively have side enclosures50 b, 51 b each formed to extend in the radial direction Y at the sideof coil end 12 a opposite to stator core 11, in other words, on theouter side in the shaft center direction. As a result, for example, iffire is caused from coil end 12 a and is about to spread to the side, ofinsulator 13 and coil end 12 a, opposite to stator core 11 in the shaftcenter X direction, the fire and smoke are blocked by side enclosures 50b, 51 b, and the fire and smoke can be prevented from coming outside ofmotor 104.

Further, non-combustible layers 50, 51 respectively have innerperipheral enclosures 50 c, 51 c each formed to extend in the shaftcenter X direction at a position on an inner peripheral side of coil end12 a and inner peripheral wall 13 c of insulator 13. Thus, for example,if fire is caused from coil end 12 a and is about to spread to the innerperipheral side, of coil end 12 a and insulator 13, in the radialdirection Y, the fire and smoke are blocked by inner peripheralenclosures 50 c, 51 c, and fire and smoke can be prevented from comingoutside of motor 104.

In the present exemplary embodiment, non-combustible layers 50, 51 havea cross-section in an approximate U-shape; however, the shape is notlimited to the U-shape, and any shape can be used as long asnon-combustible layers 50 and 51 each can well cover insulator 13 andcoil end 12 a from outside. Further, the present exemplary embodimenthas an advantage that even if fire comes out to the inner peripheralside from coil end 12 a, fire and smoke can be prevented from comingoutside of non-combustible layers 50, 51. However, the non-combustiblelayers are not limited to the above example and may be configured asshown in the half cross-sectional view of a modified example of thepresent exemplary embodiment in FIG. 11. Specifically, motor 104 a shownin FIG. 11 has, as non-combustible layers 52, 53, outer peripheralenclosures 52 a, 53 a and side enclosures 52 b, 53 b, respectively.Although motor 104 a has no inner peripheral enclosure as describedabove, fire caused from coil end 12 a can be prevented from coming outof insulator 13 and coil end 12 a to the outer peripheral side or to thelateral side. Thus, compared with the case of no non-combustible layers52, 53 provided, there is provided an effect of preventing fire fromcoming outside of motor 104 a to a certain extent.

In the case described in the above exemplary embodiments, the followingmembers are included as non-combustible layers: the parts formed toextend in the shaft center direction at the position on the outerperipheral side of coil end 12 a like non-combustible layers 41A, 41B,41C, 41D, 44, 45, 50 a, 51 a, 52 a, 53 a; and the parts formed to extendin the radial direction Y at the position on the side of coil end 12 aopposite to stator core 11 like non-combustible layers 42A, 42B, 43, 45,50 b, 51 b, 52 b, 53 b. Thus, even if fire is caused from coil end 12 a,this configuration can well prevent the fire from spreading from coilend 12 a of the motor to the outside, in other words, spreading to theoutside in the radial direction Y and the shaft center X direction,thereby preventing fire and smoke from coming outside of the motor.However, the non-combustible layers are not limited to the aboveconfiguration and may be configured as follows. A non-combustible layermay be configured with only a part formed to extend in the shaft centerX direction at a position on the outer peripheral side of coil end 12 alike non-combustible layers 41A, 41B, 41C, 41D, 44, 45, 50 a, 51 a, 52a, 53 a; or a non-combustible layer may be configured with only a partformed to extend in the radial direction Y at a position on the side ofcoil end 12 a opposite to stator core 11 like non-combustible layers42A, 42B, 43, 45, 50 b, 51 b, 52 b, 53 b. Whichever form is used, thereis an advantage that fire and smoke are less likely to come outside,compared with a motor configured to have no non-combustible layer.

Fifth Exemplary Embodiment

FIG. 12 is a half cross-sectional view of motor 105 according to a fifthexemplary embodiment of the present invention.

In the above first to fourth exemplary embodiments, for example, thecase is described where non-combustible layers such as non-combustiblelayers 44, 45 cover coil ends 12 a; however, in the present exemplaryembodiment, as shown in FIG. 12, non-combustible layers 54, 55 alsocover transition wires 12 b for coils 12. In the same way as in a normalmotor, motor 105 includes transition wires 12 b each disposed on anouter periphery of outer peripheral wall 13 b of each insulator 13 orthe like, and transition wires 12 b connect between coils 12 acrossteeth (lib). In the present exemplary embodiment, non-combustible layers54, 55 are provided to also cover transition wires 12 b.

In the present exemplary embodiment, non-combustible layers 54, 55 areeach configured with a non-combustible material such as a ring-shapedmetallic sheet. Further, non-combustible layers 54, 55 are each formedto extend in the shaft center X direction at a position on the outerperipheral side of coil end 12 a, outer peripheral wall 13 b ofinsulator 13, and transition wire 12 b. Non-combustible layers 54, 55cover transition wires 12 b in addition to coil ends 12 a and outerperipheral walls 13 b of insulators 13, from the outer peripheral side.Further, height h21, which is a dimension of each of non-combustiblelayers 54, 55 in the shaft center X direction, only has to be largeenough that if transition wire 12 b sparks and generates a spark due towire break of transition wire 12 b or other reason, the spark caused bythe sparking does not reach barrel 31 a of molding resin 31. Note thatnon-combustible layers 54, 55 may be constituted by a non-combustiblematerial such as an inorganic material or may be constituted by air. Ifnon-combustible layers 54, 55 are constituted by air, it is necessary tosecure, for non-combustible layers 54, 55, the dimension in the shaftcenter X direction, in addition, to secure a dimension in the radialdirection Y equal to height h21.

According to this configuration, motor 105 is provided withnon-combustible layers 54, 55 covering not only coil ends 12 a of coils12 of stator 10 but also transition wires 12 b. Conductive wiresconstituting coils 12 of stator 10 can break in some cases. If by anychance a safe protection circuit configured to prevent an excessivecurrent from flowing through coil 12 of stator 10 does not normallyfunction, an excessive current will flow through the conductive wireconstituting coil 12 of stator 10. Further, transition wire 12 bconnecting between coils 12 can break in some cases. At the time oftransition wire 12 b breaking, a broken part sparks and thus generates aspark in some cases. The spark generated by the sparking can ignite gasgenerated from insulator 13 or the like, and flame can be generated. Toaddress such a problem, by employing the configuration of the presentexemplary embodiment, even if a spark is generated by sparking, fire dueto insulator 13 or the like is blocked by non-combustible layers 54, 55,and fire and smoke can be prevented from coming outside of motor 105.

That is, non-combustible layers 54, 55 are each formed to extend in theshaft center X direction at a position on the outer peripheral side ofouter peripheral wall 13 b of insulator 13 and transition wire 12 b.Thus, for example, if fire is caused from transition wire 12 b and isabout to spread to the outer peripheral side, of insulator 13 andtransition wire 12 b, in the radial direction Y, the fire and smoke areblocked by non-combustible layers 54, 55, and fire and smoke areprevented from coming outside of motor 105.

In the above present exemplary embodiment, the case is described wheretwo non-combustible layers 54, 55 cover also transition wires 12 b forcoils 12; however, the non-combustible layers are not limited to theabove example. Specifically, the non-combustible layer may be configuredas shown in the half cross-sectional view of a modified example of thepresent exemplary embodiment in FIG. 13. Motor 105 a shown in FIG. 13may be configured such that one non-combustible layer 56 covers not onlycoil ends 12 a of coils 12 of stator 10 and transition wires 12 b butalso the outer peripheral side of stator core 11. With this arrangement,fire and smoke is blocked by non-combustible layer 56, and fire andsmoke can be prevented from coming outside of motor 105 a.

Further, in motors 105, 105 a shown in FIGS. 12 and 13, the case isdescribed where each of non-combustible layers 54, 55, 56 is disposedinside (inner peripheral side) of molding resin 31; however, theplacement of the non-combustible layer is not limited to the placementin the above example. Specifically, the non-combustible layer may beconfigured as shown in a half cross-sectional view of another modifiedexample of the present exemplary embodiment shown in FIG. 14. In motor105 b shown in FIG. 14, non-combustible layers 57, 58 may berespectively disposed on the inner peripheral side and the outerperipheral side of molding resin 31. Non-combustible layers 57, 58 areconstituted by a non-combustible material such as a metallic sheet orceramic.

In this modified example, as shown in FIG. 14, non-combustible layer 57is formed to extend in the shaft center X direction on the innerperipheral side of molding resin 31. In more detail, non-combustiblelayer 57 is formed to include, in the shaft center X direction, coil end12 a, insulator 13, and transition wire 12 b that are on the side closeto circuit board 34 and first bracket 32, and to include stator core 11.As described above, non-combustible layer 57 covers the above membersfrom the outer peripheral side in the radial direction Y.

In addition, on the outer peripheral side of molding resin 31 and on theouter side, of molding resin 31, on the lower side in FIG. 14,non-combustible layer 58 is formed to extend from an outer peripheralsurface of barrel 31 a of molding resin 31 to the vicinity of shaftbearing 30B, in other words, in the shaft center X direction and in theradial direction Y. More specifically, on an outer peripheral surface ofbarrel 31 a of molding resin 31, non-combustible layer 58 extends in theshaft center X direction, at a position on the outer peripheral side ofcoil end 12 a close to second bracket 33. Further, non-combustible layer58 is formed to include coil end mold 31 b in the shaft center Xdirection or to include coil end 12 a, insulator 13, transition wire 12b, and stator core 11 as in the present exemplary embodiment. Further,non-combustible layer 58 is formed to extend also in the radialdirection Y at a position on the side of coil end 12 a opposite tostator core 11 so as to include coil end mold 31 b in the radialdirection Y. With this configuration, non-combustible layer 58 coverscoil end 12 a or covers coil end 12 a, insulator 13, and transition wire12 b as in the present exemplary embodiment, in a region from end part58 a located in the direction along the shaft center X to end part 58 blocated in the radial direction Y.

Further, in this modified example, non-combustible layer 57 and end part58 a of non-combustible layer 58 overlap each other by height range h31in the shaft center X direction. In addition, end part 58 b ofnon-combustible layer 58 and second bracket 33 overlap each other in theradial direction Y by radial direction range W32.

As described above, according to the configuration of the presentmodified example, non-combustible layers 57, 58 are formed to extend inthe shaft center X direction on the inner peripheral side and the outerperipheral side of molding resin 31, at positions on the outerperipheral side of outer peripheral walls 13 b of insulators 13 andtransition wires 12 b. Thus, for example, if fire is caused fromtransition wire 12 b and is about to spread to the outer peripheralside, of insulator 13 and transition wire 12 b, in the radial directionY, the fire due to insulator 13 and the like and smoke are blocked bynon-combustible layers 57, 58, and fire and smoke can be prevented fromcoming outside of motor 105 b.

In this modified example, non-combustible layer 57 and end part 58 a ofnon-combustible layer 58 overlap each other by height range h31 in theshaft center X direction. With this arrangement, it is possible toimprove blocking performance of fire and smoke when fire is caused fromtransition wire 12 b and coil end 12 a in the vicinity ofnon-combustible layer 57 and end part 58 a, and fire and smoke can bebetter prevented from coming outside of motor 105 b. In addition, endpart 58 b of non-combustible layer 58 and second bracket 33 overlap eachother in the radial direction Y by radial direction range W32. With thisarrangement, it is possible to improve blocking performance of fire andsmoke when fire is caused from transition wire 12 b and coil end 12 a inthe vicinity of non-combustible layer 57 and end part 58 a, and fire andsmoke can be better prevented from coming outside of the motor.

Alternatively, the non-combustible layers may be configured as shown inthe half cross-sectional view of a still another modified example of thepresent exemplary embodiment shown in FIG. 15. Motor 105 c shown in FIG.15 is further provided with non-combustible layer 59 such thatnon-combustible layer 59 overlaps, on the outer peripheral side ofmolding resin 31, an end part of bulging part 57 a of non-combustiblelayer 57 by height range h33 in the shaft center X direction.Non-combustible layer 59 is constituted by a non-combustible materialsuch as a metallic sheet or ceramic. Also by non-combustible layer 59,blocking performance of fire and smoke is further improved, and fire andsmoke can be better prevented from coming outside of the motor. Notethat instead of separately providing non-combustible layer 59, it ispossible to form non-combustible layer 59 by extending, in the shaftcenter X direction, an end part, of first bracket 32, on the outerperipheral side in the radial direction.

Sixth Exemplary Embodiment

FIG. 16 is an exploded perspective view of motor 106 according to asixth exemplary embodiment of the present invention. FIG. 17 is across-sectional view of motor 106 according to the sixth exemplaryembodiment of the present invention. FIG. 18 is a plan cross-sectionalview of motor 106 according to the sixth exemplary embodiment of thepresent invention taken along line 18-18 in FIG. 17. FIG. 19 is anexternal perspective view of motor 106 according to the sixth exemplaryembodiment of the present invention. In addition, FIG. 20 is an explodedperspective view of another motor according to the sixth exemplaryembodiment of the present invention.

Also in the present exemplary embodiment, a description will be given onmotor 106 as an example of a brushless motor including permanent magnetson a rotor. Hereinafter, as show in FIG. 16, a direction represented by“X” in which rotary shaft 21 extends is a shaft direction. A descriptionwill be given supposing that, in a plane perpendicular to the shaftdirection X as shown in FIG. 18, a direction indicated by “Y” spreadingfrom center X of rotary shaft 21 is a radial direction and a directionindicated by “Z” circling around central point X is a circumferentialdirection.

Further, as shown in FIG. 17, also in the present exemplary embodiment,a non-combustible layer is provided to prevent that fire and smoke comeoutside of a main body of motor 106 due to, for example, a problem thata safe protection circuit does not normally function and an excessivecurrent thus flows through coil 62. Specifically, in the presentexemplary embodiment, a metallic cover made of metal is used as thenon-combustible layer. More specifically, the metallic cover isconfigured with metallic inner cover 66 and metallic outer cover 76.

As shown in FIG. 16, motor 106 of the present exemplary embodimentincludes stator 60, rotor 80, first bracket 35, circuit board 34, twoshaft bearings 30A and 30B, and metallic outer cover 76. Note that foreasy understanding of a configuration of motor 106, metallic inner cover(66) (to be described later) is not shown in the drawing.

As shown in FIG. 17, stator 60 includes coil assembly 64 includingstator core 61, coils 62, and insulators 63. Coil assembly 64 isassembled with coil 62 wound on stator core 61 via insulators 63 made ofan insulating material similarly to the above exemplary embodiments.

Further, as shown in FIG. 18, stator core 61 has a ring-shaped yoke 61 aand a plurality of teeth 61 b extending inward in the radial directionfrom an inner peripheral surface of yoke 61 a. The plurality of teeth 61b are disposed at the same intervals in the circumferential direction Z,forming slots 61 c, which are opening parts, each between each tooth 61b. In the present exemplary embodiment, an example is described in whichthe plurality of teeth 61 b are used to form 12 slots. On an end part ofeach extended tooth 61 b, there is formed tooth top end 61 bb that isexpanded in the circumferential direction Z such that tooth top end 61bb is wider than a tooth middle part 61 ba. An inner peripheral surfaceof each tooth top end 61 bb serves as a magnetic pole surface that facesan outer peripheral surface of rotor 80. With respect to stator core 61having the above configuration, coils 62 are formed by winding a windingwire on each tooth 61 b while inserting the winding wire into an openingof each slot 61 c. In addition, for example, transition wires asdescribed in the fifth exemplary embodiment are each used to connectbetween individual coils 62. Coils 62 each on each tooth 61 b asdescribed above are energized and driven by, for example, three-phasealternating current with a U-phase, a V-phase, and a W-phase that aredifferent in phase from each other by 120 degrees.

Further, in the present exemplary embodiment, stator 60 includes:metallic inner cover 66 made of metal being disposed to surround anouter periphery of stator core 61 as shown in FIG. 18; and secondbracket 65 disposed to protrude from stator 60 as shown in FIG. 16.Further, as shown in FIG. 17, stator 60 is integrally molded withmolding resin such that while coil assembly 64, metallic inner cover 66,and second bracket 65 are disposed at predetermined positions, the resinmaterial covers all these members except the inner peripheral surface ofeach tooth (61 b) and a projecting part of second bracket 65. Asdescribed above, stator 60 is configured to include molding resin part69 in which the above-mentioned members are integrally molded withmolding resin. Stator 60 configured as described above has anapproximately cylindrical shape, and on a columnar surface of stator 60there are formed mounting parts 69 a for attaching motor 106 to anexternal device or the like and are formed wire hole 69 b and the like.Of both circular surfaces of stator 60, one surface is open, and firstbracket 35 is attached to the opening to cover one of the openings likeputting a lid. The other surface is closed, and second bracket 65 isdisposed to protrude from the surface. The configuration of stator 60will be further described below in detail.

As shown in FIGS. 16 to 18, inside stator 60 as described above there isinserted rotor 80 with a predetermined distance between rotor 80 andstator 60 in the radial direction Y. That is, motor 106 is an innerrotor type motor, in which rotor 80 is disposed inside stator 60, andthe present exemplary embodiment takes motor 106 of the above-describedinner rotor type as an example.

Rotor 80 includes rotation body 82 holding magnets 84 centering aroundrotary shaft 21 rotatably held by shaft bearing 30A and shaft bearing30B. As shown in FIG. 17, rotation body 82 includes rotor core 83,magnets 84, and rotor resin part 86. Rotor core 83 is configured with,for example, a plurality of thin steel sheets laminated in the shaftdirection X and is fixed to rotary shaft 21 at approximately a centralpart of rotary shaft 21. Magnets 84 are permanent magnets and arearranged inside rotor core 83, in the present exemplary embodiment.

As shown in FIG. 18, in rotor core 83 there are formed a plurality ofmagnet insertion holes 83 a arranged at the same intervals in thecircumferential direction Z and penetrating through rotor core 83 in theshaft direction X. One magnet 84 is inserted in each magnet insertionhole 83 a. The present exemplary embodiment describes an interiorpermanent magnet (IPM) type motor 106, in which magnets 84 are containedin rotor core 83 as described above. An example described in the presentexemplary embodiment has 10 magnetic poles such that S pole and N poleof magnets 84 can be alternately arranged in the circumferentialdirection Z. An example of motor 106 in the present exemplary embodimentis a brushless motor having 10 poles and 12 slots.

Further, in the present exemplary embodiment, as shown in FIG. 17,rotation body 82 is configured with rotor resin part 86, and rotor resinpart 86 is formed by molding such that both ends of each magnetinsertion hole 83 a of rotor core 83 in which magnet 84 is inserted arecovered with the resin material. In the present exemplary embodiment,rotor core 83 is also provided with resin through holes 83 b penetratingthrough in the shaft direction X. Rotor resin part 86 is provided withdisk-shaped end plate resin parts 86 a formed on both end parts in anaxis direction of rotor resin part 86 such that disk-shaped end plateresin parts 86 a sandwich each magnet 84 in the shaft direction X. Inthe present exemplary embodiment, resin through holes 83 b of rotor core83 are also filled with the resin material, which connects end plateresin parts 86 a to each other with resin in the shaft direction X. Theresin material filling resin through holes 83 b constitutes inner resinparts 86 b as part of rotor resin part 86. In the present exemplaryembodiment, above-described rotor resin part 86 enables each magnet 84to be securely fixed on rotor core 83. In addition, with thisconfiguration, even if motor 106 is used for water-section devices,outdoor units of air conditioners, and the like, which are in contactwith rain water and dew condensation water, magnets 84 are preventedfrom being in contact with water. Although the present exemplaryembodiment describes above-described inner rotor type motor 106, themotor may be a surface permanent magnet motor (SPM) as shown in FIG. 20,in which magnets are held on the outer peripheral surface of rotor 80like motors described in the first to fifth exemplary embodiments

As described above, rotor 80 is configured with rotation body 82 havinga columnar shape as shown in FIG. 16 and rotary shaft 21 penetratingthrough a center of rotation body 82.

Above-described rotary shaft 21 to which rotation body 82 is fixed isrotatably supported by two shaft bearings 30A and 30B. Shaft bearings30A and 30B are each a bearing having a plurality of small diameterballs. In the present exemplary embodiment, above-described shaftbearings 30A and 30B are respectively fixed via first bracket 35 andsecond bracket 65 both made of metal and each disposed on each of bothends of stator 60 in the shaft direction.

As shown in FIGS. 16 and 17, first bracket 35 has an approximately diskshape and is configured to be attachable to an opening side of stator60. First bracket 35 has holder 35 a formed to be recessed in acylindrical shape at a central part, and holder 35 a holds shaft bearing30A. Thus, first bracket 35 in which shaft bearing 30A is inserted inholder 35 a is attached to stator 60, so that one side of rotary shaft21 is rotatably supported.

Second bracket 65 has a diameter smaller than a diameter of firstbracket 35 and has a shape in which a disk and a cylinder are combined.Further, by the above-mentioned molding, second bracket 65 is fixed tomolding resin part 69 of stator 60. Also at a central part of secondbracket 65, there is a holder 65 a formed to be recessed in acylindrical shape, and shaft bearing 30B is held by holder 65 a. Thus,by inserting shaft bearing 30B into holder 65 a, the other side ofrotary shaft 21 is rotatably supported with respect to stator 60. In thepresent exemplary embodiment, at a center of holder 65 a, there isformed opening 65 b, and rotary shaft 21 penetrates through opening 65 band protrudes outward. Then, a protruding part of rotary shaft 21 servesas output shaft 21 p for a load or the like to be connected.

A more detailed description will be given below, but in the presentexemplary embodiment, metallic outer cover 76 made of metal is attachedon second bracket 65 of stator 60. Metallic outer cover 76 has a hollowcup shape having opening part 76 h at a center. Metallic outer cover 76is attached to stator 60 such that second bracket 65 contained in stator60 penetrates through opening part 76 h of metallic outer cover 76.

The present exemplary embodiment further describes a configurationexample in which motor 106 has circuit board 34 built-in on the openingside of stator 60. Circuit board 34 of the present exemplary embodimenthas an approximately disk shape and has opening 34 b formed at a centralpart for rotary shaft 21 to go through. On circuit board 34 there aremounted electronic components (34 a) such as a drive circuit, and tocircuit board 34 there are connected connecting wires and the likethrough which a supply voltage and a control signal are applied. Then,connecting wires for connection to outside are led outside via wireholder 68 attached to wire hole 69 b.

As described above, motor 106 is configured in the following procedure.First, stator 60 is configured by integrally molding coil assembly 64,metallic inner cover 66, and second bracket 65 disposed at predeterminedpositions. Shaft bearings 30A and 30B are attached on both sides ofrotary shaft 21 of rotor 80. Then, rotor 80 to which shaft bearings 30Aand 30B are attached is inserted into stator 60 such that output shaft21 p protrudes from opening 65 b of second bracket 65. Next, shaftbearing 30B is pressed into holder 65 a of second bracket 65. Next,circuit board 34 is attached on the opening side of stator 60. Theconnecting wires connected to circuit board 34 are led outside via wireholder 68. Then, shaft bearing 30A is pressed into holder 35 a of firstbracket 35, and first bracket 35 is attached on the opening side ofstator 60 like putting a lid. Finally, metallic outer cover 76 isattached on second bracket 65 of stator 60. In this manner, motor 106 asshown in FIG. 19 is completed.

When motor 106 configured as described above is supplied with a supplyvoltage, control signals, and the like via the connecting wires, coils62 are energized and driven by the drive circuit mounted on circuitboard 34. When coils 62 are energized, drive currents flow through coils62, and stator core 61 generates a magnetic field. Then, due to analternating magnetic field from stator core 61 and magnetic fields frommagnets 84 owned by rotor 80, an attractive force and a repulsive forceare generated depending on polarities of those magnetic fields, andthese forces rotates rotor 80 in the circumferential direction Zcentering on rotary shaft 21.

Next, regarding motor 106 configured as described above, a detailedconfiguration of stator 60 including metallic inner cover 66 will bedescribed.

FIG. 21 is a cross-sectional view showing a cross-section of metallicinner cover 66 and a cross-section of tooth 61 b on which coil 62 iswound. FIG. 22 is an exploded perspective view of coil assembly 64 andmetallic inner cover 66. FIG. 23 is a configuration diagram of metallicinner cover 66 disposed on an outer periphery of coil assembly 64.

As shown in FIG. 21, insulator 63 schematically has bottom surface part63 a, outer peripheral wall 63 b, and inner peripheral wall 63 c. Bottomsurface part 63 a is formed of a surface perpendicular to the shaftdirection X. Then, the surface formed on bottom surface part 63 a isattached to an end surface, of stator core 61, in the shaft direction X.Further, outer peripheral wall 63 b and inner peripheral wall 63 c areeach formed of a wall surface parallel to the shaft direction X.Above-described outer peripheral wall 63 b is vertically provided on theouter peripheral side of a part where coil 62 is formed, and restricts acoil position. On outer peripheral wall 63 b, there is attached pin 63 dto protrude toward the side opposite to stator core 61. As shown in FIG.17, pin 63 d electrically connects coil 62 wound on tooth (61 b) andcircuit board 34 to each other. Pin 63 d penetrates through terminal cap36 and is connected to circuit board 34. Further, as shown in FIG. 21,inner peripheral wall 63 c is vertically provided on the inner side, ofouter peripheral wall 63 b, in the radial direction, and at the sametime, is provided on the inner peripheral side of the part, where coil62 is formed, and restricts the coil position.

Bottom surface part 63 a of above-described insulator 63 is attached toeach of both surfaces located on ends, of tooth 61 b, in the shaftdirection X. A winding wire is wound via the pair of insulators 63 thusattached. By performing the above work, one coil 62 is formed on statorcore 61. Then, similar coils 62 are each formed on each tooth 61 b, andcoils 62 are electrically connected to each other following apredetermined connection pattern, so that coil assembly 64 shown in FIG.22 is completed.

As shown in FIG. 21, in coil assembly 64 formed as described above, coil62 has coil ends 62 a protruding from stator core 61 to both sides inthe shaft direction X. On the other hand, as shown in FIG. 18, a part,of each coil 62, other than coil ends 62 a is included in correspondingslot 61 c of stator core 61. Further, in order to electrically connectcoils 62 to each other, transition wires 62 b for connecting betweencoils 62 are disposed, across teeth (61 b), on an outer periphery of anouter peripheral wall 63 b of each insulator 63 or other places.

In this case, as described in the above background art and the like, ina motor including above-described coil assembly 64, if by any chance asafety protection function for preventing an excessive current fromflowing through coil 62 does not normally operate, the excessive currentwill flow through coil 62. Then, coil 62 or transition wire 62 bgenerates heat and heats up to extremely high temperatures. As a result,a layer short can occur, a spark can be generated due to the layershort, or the generated spark can ignite gas generated from insulator 63and the like, and flame can be generated. There is a high possibilitythat such a problem may arise particularly with the above-mentioned coilends 62 a and transition wires 62 b because coil ends 62 a andtransition wires 62 b protrude from stator core 61.

To address the problem, for example, similarly to the fifth exemplaryembodiment, also in the present exemplary embodiment, metallic innercover 66 as a non-combustible layer is disposed outside of coil assembly64 as shown in FIG. 23. As shown in FIGS. 21 and 22, metallic innercover 66 is a cylinder made of metal having an approximately cylindricalshape and having open ends on both sides. In the present exemplaryembodiment, above-described metallic inner cover 66 is disposed tosurround the outer periphery of coil assembly 64 and to have apredetermined clearance in the radial direction between the outerperiphery of coil assembly 64 and metallic inner cover 66. Metallicinner cover 66 further has small-diameter part 66 a and large-diameterpart 66 b having a larger diameter than small-diameter part 66 a asshown in FIG. 22.

In order to make it possible to fit small-diameter part 66 a to theouter periphery of stator core 61, an inner diameter of small-diameterpart 66 a is made approximately equal to an outer diameter of statorcore 61. Further, a dimension of small-diameter part 66 a in the shaftdirection X is also made approximately equal to a dimension of statorcore 61 in the shaft direction X. Due to these settings, when metallicinner cover 66 is fit to coil assembly 64 such that an outer peripheralsurface of stator core 61 and an inner peripheral surface ofsmall-diameter part 66 a of metallic inner cover 66 are joined to eachother, metallic inner cover 66 is simply fixed to coil assembly 64temporarily as shown in FIG. 23.

Further, as shown in FIG. 21, a dimension of large-diameter part 66 b inthe shaft direction X is greater than a dimension of coil end 62 a inthe shaft direction X. In metallic inner cover 66, above-describedlarge-diameter part 66 b is provided only on one side, of small-diameterpart 66 a, in the shaft direction X. When above-described metallic innercover 66 is attached to coil assembly 64, large-diameter part 66 b ofmetallic inner cover 66 is disposed to surround coil end 62 a andtransition wire 62 b on one side in the shaft direction X.

Note that in FIG. 21, in order to more clearly illustrate the placementof metallic inner cover 66, insulator 63, coil end 62 a, transition wire62 b, and the like are separately shown as follows as well.Specifically, in FIG. 21, on one side, of stator core 61, in shaftdirection X, insulator 63B, coil end 62 aB, and transition wire 62 bBare disposed; and on the other side of stator core 61, insulator 63T,coil end 62 aT, and transition wire 62 bT are disposed.

That is, as shown in FIG. 21, metallic inner cover 66 is disposed suchthat large-diameter part 66 b surrounds insulator 63B, coil end 62 aB,and transition wire 62 bB. On the other hand, any of insulator 63T, coilend 62 aT, and transition wire 62 bT is not surrounded by metallic innercover 66. In particular, on an outer periphery of insulator 63T locatedon the lower part in the drawing, there is provided positioning part 63e, which is not included in insulator 63B located on the upper part inthe drawing. Since insulator 63T has positioning part 63 e, whenmetallic inner cover 66 is attached, the positional relationshipsbetween small-diameter part 66 a and stator core 61 and betweenlarge-diameter part 66 b and insulator 63B are uniquely determined.

Further, in metallic inner cover 66 according to the present exemplaryembodiment, large-diameter part 66 b is formed to have a diameter largerthan the diameter of small-diameter part 66 a. Therefore, large-diameterpart 66 b is attached to stator core 61 with an enough insulationdistance between large-diameter part 66 b and pin 63 d. As shown in FIG.17, between large-diameter part (66 b) and pin 63 d, there is a sidewall of terminal cap 36. If terminal cap 36 is formed of an insulatingmaterial, it is possible to secure the insulation distance betweenlarge-diameter part (66 b) and pin 63 d with a larger margin.

As described above, large-diameter part 66 b of metallic inner cover 66as a non-combustible layer is disposed on the outer peripheral side ofcoil end 62 aB, outer peripheral wall 63 b of insulator 63B, andtransition wire 62 bB. Therefore, even if fire is caused from coil 62due to the above-mentioned problem caused by a layer short or the likeand the fire is about to spread from insulator 63B and transition wire62 bB to the outer peripheral side in the radial direction, the fire andsmoke is blocked by large-diameter part 66 b of metallic inner cover 66,and the fire and smoke are prevented from coming outside of motor 106.

Further, as mentioned above, regarding the configuration as shown inFIG. 23 in which fire protection measures are taken, the configurationexcept the inner peripheral surface of each tooth 61 b is covered withthe resin material of molding resin part 69. That is, for example, inthe fifth exemplary embodiment, insulators 13 and coil ends 12 a inaddition to the inner peripheral surface of each tooth 11 b are exposed.However, in the present exemplary embodiment, only the inner peripheralsurfaces of teeth 11 b are exposed. In other words, in the presentexemplary embodiment, the resin material covers the whole of insulators63 and coil ends 62 a in addition to the whole of metallic inner cover66. In the present exemplary embodiment, since the above-describedconfiguration is employed, the above-mentioned fire protection measuresare taken, and holding strength of coil assembly 64 in stator 60 is alsosufficiently secured.

Further, as shown in FIG. 15, both of insulators 13 used in the fifthexemplary embodiment each have protrusion 63 f protruding in the radialdirection Y. Therefore, in the case of the present configuration, ifnon-combustible layer 57, in particular, non-combustible layer 57 madeof the metallic material is attached to stator core 11, there is a needfor a manufacturing step in which a plate-shaped metallic material iswrapped around stator core 11.

In contrast, if insulators 63T and 63B according to the presentexemplary embodiment are used, metallic inner cover 66 having acylindrical shape can be used. Therefore, the work of attaching metallicinner cover 66 to stator core 61 can be easy, and the productivity isthus improved.

As shown in FIG. 17, in addition to the above-described fire protectionmeasures in stator 60, metallic outer cover 76 is further provided as anon-combustible layer in the present exemplary embodiment. Metallicouter cover 76 is attached to an outer surface of molding resin part 69of stator 60. In the present exemplary embodiment, metallic outer cover76 is attached to an outer side of stator 60 on a side closer to outputshaft 21 p. In addition, since metallic outer cover 76 is attached asdescribed above, metallic outer cover 76 is disposed, in the shaftdirection X, at a position on the side of stator core 61 opposite tolarge-diameter part (66 b) of metallic inner cover 66.

FIG. 24 is a drawing for describing metallic outer cover 76. In order toillustrate a positional relationship between metallic outer cover 76 andother members, FIG. 24 shows together with metallic outer cover 76 alsocoil assembly 64, metallic inner cover 66, and second bracket 65. Sincemetallic outer cover 76 is attached as shown in FIG. 17, metallic outercover 76 is disposed, in the shaft direction X, at a position on theside of stator core 61 opposite to large-diameter part 66 b of metallicinner cover 66 as shown in FIG. 24. In this case, as described above, onthe opposite side of large-diameter part 66 b, insulator 63T, coil end62 aT, and transition wire 62 bT are disposed together with secondbracket 65 from which output shaft (21 p) protrudes. Note that adescription will be given hereinafter supposing appropriately that inthe shaft direction X, a side of above-described stator core 61 oppositeto large-diameter part 66 b of metallic inner cover 66 is defined as anoutput shaft side, on which output shaft (21 p) is disposed, andsupposing that an opposite side of the output shaft side is defined asan opposite output shaft side.

Metallic outer cover 76 is configured with top surface 76 a, curvedsurface 76 b, and cylindrical part 76 c and has a hollow cup shape. Topsurface 76 a of metallic outer cover 76 has a disk shape and openingpart 76 h at a center of top surface 76 a. Curved surface 76 b is curvedin a curved surface shape at approximately a right angle from topsurface 76 a. Cylindrical part 76 c extends in a cylindrical shape fromcurved surface 76 b and has an opening on an end side of cylindricalpart 76 c. Further, in order to make it easy to fit cylindrical part 76c to an outer periphery of stator 60, an inner diameter of cylindricalpart 76 c is made approximately equal to an outer diameter of stator 60.

Further, a dimension of metallic outer cover 76 in the shaft direction Xwhen metallic outer cover 76 is attached to stator 60 is set to such adimension that cylindrical part 76 c and metallic inner cover 66 cancreate overlapping part 76 ca in the shaft direction X. In other words,metallic outer cover 76 is attached at such a position that cylindricalpart 76 c and stator core 61 can create overlapping part 76 ca in theshaft direction X when metallic outer cover 76 is attached to stator 60.In the specific example described here, overlapping part 76 ca isdimension h61.

In this manner, in the present exemplary embodiment, on the output shaftside, at least a part of cylindrical part 76 c overlaps, as overlappingpart 76 ca, stator core 61 in the shaft direction X. Further, metallicouter cover 76 is disposed with respect to coil assembly 64 such thatoverlapping part 76 ca of cylindrical part 76 c surrounds an outer sideof the outer periphery of stator core 61, having a predetermined spacebetween the outer periphery of stator core 61 and overlapping part 76 cain the radial direction Y. In the above-described positionalrelationship of metallic outer cover 76 with respect to coil assembly64, metallic outer cover 76 is attached to stator 60. As a result, onthe output shaft side, metallic outer cover 76 surrounds and coversinsulator 63T, coil end 62 aT, and transition wire 62 bT.

In this manner, coil end 62 aT, insulator 63T, and transition wire 62 bTare covered by metallic outer cover 76, which is a non-combustiblelayer. Therefore, even if fire is caused due to the above-mentionedproblem caused by a layer short or the like, and the fire is about tospread from insulator 63B and transition wire 62 bB to the outerperipheral side in the radial direction, the fire and smoke is blockedby metallic outer cover 76, and the fire and smoke can be prevented fromcoming outside of motor 106.

Further, also in the present exemplary embodiment, similarly to theconfigurations of FIGS. 14 and 15 of the fifth exemplary embodiment, atleast a part of top surface 76 a of metallic outer cover 76 overlaps, asoverlapping part 76 aa, second bracket 65 in the radial direction Y. Inmore detail, a part, of top surface 76 a, on an outer side of an outerperiphery of opening part 76 h is annular overlapping part 76 aa thatoverlaps, in the radial direction Y, a part on the outer peripheral sideof second bracket 65. Further, FIG. 24 shows an example in whichoverlapping part 76 aa has dimension w62. As described above, also inthe present exemplary embodiment, since metallic outer cover 76 andsecond bracket 65 are made to overlap each other on overlapping part 76aa, blocking performance of preventing the fire and smoke caused insidemotor 106 from coming outside is improved.

As described above, motor 106 of the present exemplary embodimentincludes metallic inner cover 66 and metallic outer cover 76 eachserving as a non-combustible layer.

By molding stator core 61 and metallic inner cover 66 attached to a sidesurface of stator core 61 as described above, stator 60 is configured toinclude molding resin part 69 integrating these members. Inabove-described stator 60, on the opposite output shaft side,large-diameter part 66 b of metallic inner cover 66 is disposed tosurround insulator 63B, coil end 62 aB, and transition wire 62 bB.Therefore, on the opposite output shaft side, large-diameter part 66 bof metallic inner cover 66 can block the fire and smoke caused insidemotor 106.

Further, in the present exemplary embodiment, metallic outer cover 76 isfit in the outer periphery of stator 60 in the above-described manner.With this arrangement, on the output shaft side, metallic outer cover 76is disposed to cover insulator 63T, coil end 62 aT, and transition wire62 bT. Therefore, on the output shaft side, metallic outer cover 76 canblock the fire and smoke caused inside motor 106.

In the present exemplary embodiment, molding resin part 69 covers thewhole of insulators 63 and coil ends 62 a in addition to the whole ofmetallic inner cover 66 while only inner peripheral surface of eachtooth 11 b is exposed. As a result, the above-described fire protectionmeasures are taken, and holding strength of coil assembly 64 in stator60 is sufficiently secured.

Although, in the present exemplary embodiment, metallic inner cover 66and metallic outer cover 76, which are made of metal, are described asnon-combustible layers, metallic inner cover 66 and metallic outer cover76 only have to be made of a non-combustible material. Metallic innercover 66 and metallic outer cover 76 may be made of a material otherthan metal such as ceramic, which is a non-combustible material.

Seventh Exemplary Embodiment

FIG. 25 is a cross-sectional view of motor 107 according to a seventhexemplary embodiment of the present invention. FIG. 26 is a perspectiveview of metallic inner cover 661 of motor 107 according to the seventhexemplary embodiment of the present invention. FIG. 27 is across-sectional view of metallic inner cover 661 and coil assembly 641of motor 107 according to the seventh exemplary embodiment of thepresent invention.

Compared with the sixth exemplary embodiment shown in FIG. 17, motor 107in the present exemplary embodiment includes: metallic inner cover 661that is a modification of metallic inner cover 66 of the sixth exemplaryembodiment; and insulator 631 that is a modification of insulator 63 ofthe sixth exemplary embodiment. As shown in FIG. 25, motor 107 includesstator 601 including molding resin part 69 made by integrating metallicinner cover 661, coil assembly 641, and insulator 631 such that metallicinner cover 661 is attached to coil assembly 641 including insulator631. However, the configuration and operation except the abovearrangement is identical to the configuration of the sixth exemplaryembodiment, and components identical to the components of the sixthexemplary embodiment are assigned the same reference marks, and thedescription of the sixth exemplary embodiment is used.

First, as shown in FIG. 26, metallic inner cover 661 as anon-combustible layer is also a cylinder made of metal having anapproximately cylindrical shape and having open ends on both sides.Further, metallic inner cover 661 further has tapered part 661 c inaddition to small-diameter part 66 a and large-diameter part 66 bsimilar to the corresponding members of metallic inner cover 66 of thesixth exemplary embodiment.

Tapered part 661 c is provided on an end part on the side ofsmall-diameter part 66 a opposite to large-diameter part 66 b. Taperedpart 661 c has an inverse tapered shape, and a diameter of tapered part661 c becomes larger from a boundary between tapered part 661 c andsmall-diameter part 66 a of metallic inner cover 661 toward an end part.

Further, in the present exemplary embodiment, in addition to taperedpart 661 c, coil assembly 641 has insulator 631 different from insulator63 of the sixth exemplary embodiment.

Specifically, as shown in FIG. 27, in coil assembly 641 in the presentexemplary embodiment, insulator 63 similar to that in the sixthexemplary embodiment is disposed on the opposite output shaft side, andinsulator 631 is disposed on the output shaft side. Insulator 631 hasbottom surface part 63 a, outer peripheral wall 63 b, and innerperipheral wall 63 c similar to those in the sixth exemplary embodiment,and further has tapered part 631 c. When insulator 631 is attached tostator core 61 on the output shaft side, tapered part 631 c is disposedon an outer periphery of stator core 61. Tapered part 631 c has atriangular cross-section and has an inverse tapered shape as a whole, adiameter of tapered part 631 c becomes larger toward an end part ofstator core 61. Further, tapered part 631 c is formed to haveapproximately the same angle of side surface and length in the shaftdirection X as tapered part 661 c of metallic inner cover 661.

When metallic inner cover 661 having above-mentioned tapered part 661 cis gradually fit into coil assembly 641 having above-described taperedpart 631 c, tapered part 661 c functions as a stopper at the time whentapered part 661 c comes into contact with tapered part 631 c, so thatmetallic inner cover 661 cannot be fit into any further. As describedabove, in the present exemplary embodiment, tapered part 661 c andtapered part 631 c restrict the position, in the shaft direction X, ofmetallic inner cover 661 with respect to coil assembly 641.

As described above, in the present exemplary embodiment, coil assembly641 includes insulator 631 having tapered part 631 c, and metallic innercover 661 includes tapered part 661 c whose shape coincides with theshape of tapered part 631 c. Therefore, in the present exemplaryembodiment, metallic inner cover 661 can be easily fit into coilassembly 641. In particular, since the above-described tapered shapesachieve a stopper function, metallic inner cover 661 can be more easilyfit into. In addition, by such a simple operation as fitting metallicinner cover 661 into until tapered part 661 c and tapered part 631 ccome in contact with each other, coil assembly 641 and metallic innercover 661 can be accurately aligned with each other in the shaftdirection X without error in positional relationship. Large-diameterpart 66 b of metallic inner cover 661 can therefore be disposedaccurately around insulator 63, coil end 62 aB, and transition wire 62bB located on the opposite output shaft side. As a result, with thepresent exemplary embodiment, since large-diameter part 66 b of metallicinner cover 661 as a non-combustible layer can be more accuratelydisposed, fire and smoke can be more surely prevented from comingoutside of motor 107.

Eighth Exemplary Embodiment

FIG. 28 is a cross-sectional view of motor 108 according to an eighthexemplary embodiment of the present invention. FIG. 29 is an enlargedperspective view of the vicinity of notch 692 a of motor 108 accordingto the eighth exemplary embodiment of the present invention. FIG. 30 isa plan cross-sectional view of motor 108 according to the eighthexemplary embodiment of the present invention taken along line 30-30 inFIG. 29. In addition, FIG. 31 is an enlarged perspective view of thevicinity of another notch of the motor according to the eighth exemplaryembodiment of the present invention.

Compared with the sixth exemplary embodiment shown in FIG. 17, motor 108in the present exemplary embodiment includes molding resin part 692 thatis a modification of molding resin part 69 of the sixth exemplaryembodiment. Specifically, as shown in FIG. 28, molding resin part 692 ofmotor 108 further includes notch 692 a in molding resin part 69 of thesixth exemplary embodiment. However, the configuration and operationexcept the above arrangement is identical to the configuration of thesixth exemplary embodiment, and components identical to the componentsof the sixth exemplary embodiment are assigned the same reference marks,and the description of the sixth exemplary embodiment is used. Inaddition, a detailed description will be given next, but in the presentexemplary embodiment, notch 692 a is used to release water due to dewcondensation and the like in metallic outer cover 76, from the main bodyof motor 108.

Notch 692 a formed in molding resin part 692 has a shape in which, on anapproximately circular-shaped cross-section of molding resin part 692 asshown in FIG. 30, a part of molding resin part 692 near an outerperiphery of molding resin part 692 is recessed toward a centraldirection of the approximately circular shape. Further, as shown in FIG.29, the above-described cross-sectional shape of notch 692 a continuesin the shaft direction X. In other words, notch 692 a is a groove orrecess formed by notching a part of molding resin part 692.

In the present exemplary embodiment, notch 692 a is formed on the sideof molding resin part 692 to which metallic outer cover 76 is attached.Further, notch 692 a is formed such that when metallic outer cover 76 isattached to molding resin part 692, notch 692 a and cylindrical part 76c of metallic outer cover 76 partially overlap each other as shown inFIG. 29. In other words, when metallic outer cover 76 is attached tomolding resin part 692, notch 692 a extends beyond the end part ofmetallic outer cover 76 to the opposite output shaft side in the shaftdirection X. As described above, in the present exemplary embodiment,notch 692 a is provided with notch opening 692 a 1 that is an opening onwhich notch 692 a and cylindrical part 76 c of metallic outer cover 76do not face each other in the radial direction Y.

In addition, in the present exemplary embodiment, notch 692 a is formedsuch that notch 692 a and wire hole 69 b to which wire holder 68 isattached are approximately at the same position in the circumferentialdirection Z. In other words, wire hole 69 b and wire holder 68 aredisposed on a line extended, in the shaft direction X, from an end partof notch 692 a on the opposite output shaft side.

Metallic outer cover 76 is attached to molding resin part 692, in anexposed state. In addition, since metallic outer cover 76 is made ofmetal, dew condensation occurs more easily, and water easily gathers,for example, between molding resin part 692 and metallic outer cover 76.To address this issue, in the present exemplary embodiment, theabove-mentioned groove-shaped notch 692 a is provided to lead waterformed in the vicinity of metallic outer cover 76 away from metallicouter cover 76.

In FIG. 29, an arrow mark is used to show an example of a path for thewater to flow through. That is, motor 108 is fixed in a device or thelike such that notch 692 a and wire holder 68 are located on the lowerside in the vertical direction. Then, water formed between molding resinpart 692 and metallic outer cover 76 is first led to notch 692 a.Further, the water flows from notch opening 692 a 1 of notch 692 a to anouter surface of molding resin part 692. Further, the water having flownout flows along a ground side surface of molding resin part 692 and thenreaches wire holder 68. Then, if a lead wire from wire holder 68 is ledin a manner to deal with water, it is possible to use the lead wire tolead the water having reached wire holder 68 further away from motor108.

As described above, in the present exemplary embodiment, molding resinpart 692 has notch 692 a as mentioned above. As a result, with thepresent exemplary embodiment, even if water is attached to metallicouter cover 76 for preventing fire and smoke from coming outside ofmotor 108 due to dew condensation or the like, the water can be led awayfrom motor 108.

FIG. 31 shows a modified example of the present exemplary embodiment.FIG. 31 is an enlarged perspective view of the vicinity of another notchof the motor according to the eighth exemplary embodiment of the presentinvention.

The difference from the above-mentioned aspect shown in FIG. 28 to FIG.30 is that tapered parts 76 d and 692 a 2 are formed in the vicinity ofnotch opening 692 a 1 in the modified example. The other components areassigned the same reference marks as in the aspects in FIGS. 28 to 30,and the corresponding descriptions are used.

Specifically, as shown in FIG. 31, in the vicinity of notch opening 692a 1, an end part, of metallic outer cover 76, on the opposite outputshaft side has tapered part 76 d opened in the radial direction Y.Similarly, molding resin part 692 has tapered part 692 a 2 at a positionfacing tapered part 76 d. Tapered part 76 d and tapered part 692 a 2constitute inclined surfaces opened downward in the vertical directionsuch that the water having passed through notch 692 a is smoothlydischarged. As a result, the water having passed through notch 692 a ismore surely led outside of notch 692 a.

Ninth Exemplary Embodiment

FIG. 32 is a cross-sectional view of motor 109 according to a ninthexemplary embodiment of the present invention. FIG. 33 is an enlargedview of the vicinity of metallic outer cover 763 of motor 109 accordingto the ninth exemplary embodiment of the present invention.

Compared with the sixth exemplary embodiment shown in FIG. 17, motor 109in the present exemplary embodiment includes metallic outer cover 763that is a modification of metallic outer cover 76 of the sixth exemplaryembodiment. Specifically, as shown in FIG. 32 and FIG. 33, metallicouter cover 763 of motor 109 further includes edge part 763 d havingchamfered part 763 d 1 on metallic outer cover 76 of the sixth exemplaryembodiment. However, the configuration and operation except the abovearrangement is identical to the configuration of the sixth exemplaryembodiment, and components identical to the components of the sixthexemplary embodiment are assigned the same reference marks, and thedescription of the sixth exemplary embodiment is used.

As shown in FIG. 33, metallic outer cover 763 further has chamfered part763 d 1 on edge part 763 d, which is a curved surface as a so-called“chamfer”, in the opening side of metallic outer cover 763. In thepresent exemplary embodiment, since edge part 763 d is rounded byproviding chamfered part 763 d 1, metallic outer cover 763 can be easilyattached to molding resin part 69. In addition, since edge part 763 d ismade as described above, injury, damage, and the like caused by a sharpedge are prevented. Note that chamfered part 763 d 1 may be a flatchamfer instead of a rounded chamfer.

FIG. 34 is a partial cross-sectional view showing a modified example ofthe present exemplary embodiment. As shown in FIG. 34, in this modifiedexample, edge part 763 d on the opening side of metallic outer cover 763is tapered part 763 d 2 having an inverse tapered shape. A diameter oftapered part 763 d 2 becomes larger toward the opposite output shaftside. This configuration also makes it easy to attach metallic outercover 763 to molding resin part 69.

Tenth Exemplary Embodiment

FIG. 35 is a plan cross-sectional view of coil assembly 644 of motor 110of a tenth exemplary embodiment of the present invention, where metallicinner cover 66 is fit on coil assembly 644 but a swaging process is notperformed yet. FIG. 36 is an enlarged cross-sectional view of A-A partof FIG. 35, where metallic inner cover 66 is attached to coil assembly644 and a swaging process has been performed. FIG. 37 is a perspectiveview showing an outer appearance of coil assembly 644 of motor 110according to the tenth exemplary embodiment of the present invention.

Compared with the sixth exemplary embodiment shown in FIGS. 17 and 18,motor 110 in the present exemplary embodiment includes: stator core 614of coil assembly 644 that is a modification of stator core 61 of coilassembly 64; and metallic inner cover 664 made by modifying metallicinner cover 66 of the sixth exemplary embodiment by a swaging process.Specifically, as shown in FIG. 35, motor 110 includes a stator includingmetallic inner cover 664 made by fitting metallic inner cover 66 on coilassembly 644 and then performing a swaging process on metallic innercover 66. However, the configuration and operation except the abovearrangement is identical to the configuration of the sixth exemplaryembodiment, and components identical to the components of the sixthexemplary embodiment are assigned the same reference marks, and thedescription of the sixth exemplary embodiment is used.

Since the swaging process is performed as described above, protrusions61 d are formed on an outer periphery of stator core 614 as shown inFIGS. 36 and 37 in the present exemplary embodiment. At least oneprotrusion 61 d only has to be formed, and in an example shown in thepresent exemplary embodiment, 12 protrusions 61 d are formed, which isthe same in number as teeth 61 b. In the present exemplary embodiment,above-described protrusions 61 d are formed on the outer periphery ofstator core 614 at constant intervals in the circumferential directionZ. Each protrusion 61 d extends in the shaft direction X and has atriangular shape protruding in the radial direction Y as shown in FIG.36.

Further, in a step of assembling the stator of the present exemplaryembodiment, metallic inner cover 66, which is the same as in the sixthexemplary embodiment and the like, is first fit on stator core 614having these protrusions 61 d. In this step, metallic inner cover 66 isfit on with an end of each protrusion 61 d protruding in a triangularshape being in contact with an inner peripheral surface of metallicinner cover 66. That is, in the present exemplary embodiment,protrusions 61 d make it possible to fit in metallic inner cover 66while metallic inner cover 66 and stator core 614 are in contact witheach other on a small contact area, and the workability can beaccordingly improved.

In addition, in the present exemplary embodiment, after metallic innercover 66 is fit on coil assembly 644, a swaging process with a swagingtool is performed on parts where protrusions 61 d are located, fromoutside of metallic inner cover 66. Specifically, as shown in FIG. 36,the swaging tool having a triangular recess is pressed, from outside,against metallic inner cover 66 at a part where each protrusion 61 d islocated. With this process, the pressed parts of metallic inner cover 66become protrusions each of which is curved in a triangular shape asshown in FIG. 36. In other words, with the above-described swagingprocess, metallic inner cover 664 having swaged parts 664 c as theprotrusions as shown in FIG. 36 is completed. In addition, of course,after the swaging process, an outer peripheral side of each protrusion61 d of stator core 614 and an inner peripheral side of correspondingswaged part 664 c of metallic inner cover 664 are in contact with eachother while meshing with each other in a triangular form as shown inFIG. 36.

As described above, in the present exemplary embodiment, at least oneprotrusion 61 d is formed on stator core 614, and swaged part 664 c isformed on metallic inner cover 664, corresponding to protrusion 61 d.Then, metallic inner cover 664 is held on coil assembly 64 by protrusion61 d and swaged part 664 c. Thus, it is possible to prevent positionaldeviation from each other, for example, at the time of molding. As aresult, with the present exemplary embodiment, it is possible to preventlarge-diameter part (66 b) of metallic inner cover 664 as anon-combustible layer from being deviated from a predetermined positionand other problematic issues; therefore, fire and smoke can be moresurely prevented from coming outside of motor 110.

Although, in the present exemplary embodiment, a description is given toan example in which metallic inner cover 664 is held on coil assembly 64on the basis of a swaging process, metallic inner cover 664 may be heldby a spot-welding method. Specifically, after metallic inner cover 66 isfit on stator core 614 having protrusions 61 d as mentioned above, aspot-welding method may be performed on parts at which protrusions 61 dand metallic inner cover 66 are in contact with each other to fixmetallic inner cover 66 on stator core 614.

Eleventh Exemplary Embodiment

FIG. 38 is a cross-sectional view of motor 111 according to an eleventhexemplary embodiment of the present invention. FIG. 39 is an explodedperspective view of terminal cap 365, metallic inner cover 66, and coilassembly 64 of motor 111 according to the eleventh exemplary embodimentof the present invention.

Compared with the sixth exemplary embodiment shown in FIG. 17, motor 111in the present exemplary embodiment includes terminal cap 365 that is amodification of terminal cap 36 of the sixth exemplary embodiment.Specifically, as shown in FIGS. 38 and 39, terminal cap 365 of motor 111further includes wall 365 b on terminal cap 36 of the sixth exemplaryembodiment. However, the configuration and operation except the abovearrangement is identical to the configuration of the sixth exemplaryembodiment, and components identical to the components of the sixthexemplary embodiment are assigned the same reference marks, and thedescription of the sixth exemplary embodiment is used.

As shown in FIG. 39, terminal cap 365 includes wall 365 b in addition toterminal face 365 a having terminals for electric connection. Further,terminal cap 365 is formed of resin having insulation property as aninsulating material. In the present exemplary embodiment,above-described terminal caps 365 are disposed on the opposite outputshaft side in motor 111 As shown in FIG. 39, terminal cap 365 isdisposed such that terminal face 365 a faces coil assembly 64. Inaddition, wall 365 b extends in the shaft direction X from an outerperipheral side of terminal face 365 a. That is, wall 365 b is parallelto large-diameter part 66 b of metallic inner cover 66. Wall 365 b isdisposed between large-diameter part 66 b and outer peripheral walls 63b included in insulators 63, in the radial direction Y. Between wall 365b and coil ends 62 a, outer peripheral wall 63 b is located.

As described above, in the present exemplary embodiment, terminal cap365 includes wall 365 b. With the present exemplary embodiment, thisconfiguration prevents the terminals disposed on terminal face 365 a andmetallic inner cover 66 from being in contact with each other, therebyimproving safety.

Twelfth Exemplary Embodiment

FIG. 40 is a partially enlarged cross-sectional view of motor 112according to a twelfth exemplary embodiment of the present invention.

Compared with the sixth exemplary embodiment shown in FIG. 17, motor 112in the present exemplary embodiment includes: molding resin part 696that is a modification of molding resin part 69 of the sixth exemplaryembodiment; and metallic outer cover 766 that is a modification ofmetallic outer cover 76 of the sixth exemplary embodiment. Specifically,as shown in FIG. 40, motor 112 has recess 696 a formed in molding resinpart 696 and has bent part 766 d 1 on edge part 766 d of metallic outercover 766. However, the configuration and operation except the abovearrangement is identical to the configuration of the sixth exemplaryembodiment, and components identical to the components of the sixthexemplary embodiment are assigned the same reference marks, and thedescription of the sixth exemplary embodiment is used.

At least one recess 696 a is formed in the outer periphery of moldingresin part 696, at a position closer to the output shaft. Further, bentpart 766 d 1 is formed corresponding to recess 696 a on edge part 766 d,of metallic outer cover 766, on the opening part side. In the aboveconfiguration, when metallic outer cover 766 is attached to moldingresin part 696, bent part 766 d 1 meshes with recess 696 a. Therefore,with the present exemplary embodiment, metallic outer cover 766 can beeasily attached to and fixed on molding resin part 696.

As apparent from the above description, the present disclosure improvessafety of a motor itself even in the case where a safety protectiondevice does not normally function when the motor is driven. In otherwords, an object of the present disclosure is to prevent fire and smokefrom coming outside of a motor under an unusual environment.

Specifically, as described above, if an excessive current is kept beingsupplied to a motor while a safety protection device does not normallyfunction, the excessive current continues to flow through a coil. Inthis case, if a problem has occurred with a winding wire constitutingthe coil and a layer short has occurred in the coil, the coil can be aheat source.

The present disclosure prevents the above-mentioned fire and smoke fromflowing out by surrounding the coil, which can be a heat source, with anon-combustible layer. For the non-combustible layer, it is possible touse non-combustible materials such as air, a metallic material, andceramic.

In a motor, a rotor rotates around a rotary shaft in general. For thisreason, an outer shape of a motor generally has an approximatelycolumnar shape extending in a rotary shaft direction. Therefore, anon-combustible layer according to the present disclosure needs tosurround a coil on a side surface side of the columnar shape and abottom surface side and an upper surface side of the columnar shape.

When an inner rotor type motor is taken into consideration, it is idealto directly surround a coil, which can be a heat source, or to surrounda coil assembly with a non-combustible layer. However, the coil is woundon a stator. In other words, inside the coil assembly, the rotor islocated, being fixed to the rotary shaft. Therefore, these memberscannot be directly surrounded easily by a non-combustible layer.

To address this issue, the applicants of the present application haveconceived the above-mentioned exemplary embodiments in which the coil orthe coil assembly on a part possible to be surrounded is surrounded inthe closest place and in which the coil or the coil assembly on a partimpossible to be surrounded is surrounded in a possible range.

For example, in particular, the sixth exemplary embodiment, which isconsidered useful in terms of electromagnetic compatibility (EMC) andmanufacturing, is configured as follows.

Specifically, a metallic inner cover is directly attached to a statorcore on which a coil is wound such that the metallic inner coverincludes a side surface side of a coil end located on an opposite outputshaft side.

The other parts, that is, a side surface side of the coil end located onan output shaft side and a bottom surface side and an upper surface sideof each of the coil ends located on the output shaft side and theopposite output are surrounded by a first and second brackets and ametallic outer cover.

With the present configuration, an entire periphery of the coil assemblycan be directly or indirectly surrounded. Therefore, when the presentexemplary embodiment is employed, it is achieved that fire and smoke isprevented from coming outside of a motor under an unusual environment,which is an object of the present disclosure. In addition, it ispossible to easily achieve a feature of a molded motor, that is,suppression of sound and vibration or a form including various outershapes, such as presence or absence of a mounting part.

In other words, if the outer surface of a motor is surrounded by ametallic cover, it is possible to prevent fire and smoke from comingoutside of the motor under an unusual environment, which is a mainpurpose. However, the following points should be considered.

In order to cover all of the outer surface of a motor with a metalliccover, it is necessary to prepare many metallic covers corresponding tovarious outer shapes such as presence or absence of a mounting part.Therefore, since it is necessary to carry a variety of inventory interms of manufacturing, productivity needs to be improved.

In addition, there will be a small gap created between an outer surfaceof a motor and a metallic cover. This gap functions as an air layer.Specifically, this air gap functions to inhibit dissipation of heat ofthe motor when the motor is normally used. Therefore, there needs to beimprovement in terms of cooling the motor.

Further, if the outer surface of a motor is surrounded by a metalliccover and the motor is used being attached to an electric device, themetallic cover acts as an antenna. Therefore, there needs to be furtherimprovement in EMC resistance.

Therefore, in view of the spirit of the present disclosure, it is notintended to exclude a form in which an outer surface of a motor iscovered with a metallic cover, but the above-mentioned exemplaryembodiments are more preferable in which a coil or a coil assembly iscovered at a closer position.

INDUSTRIAL APPLICABILITY

The present invention can be widely used in a field of a so-calledmolded motor in which a stator is covered with molding resin.

REFERENCE MARKS IN THE DRAWINGS

-   -   101, 101 a, 102, 103, 104, 104 a, 105, 105 a, 105 b, 105 c, 106,        107, 108, 109, 110, 111, 112, 900: motor    -   10, 60, 601, 910: stator    -   11, 61, 614, 911: stator core    -   11 a, 61 a: yoke    -   11 b, 61 b: teeth (tooth)    -   12, 62, 912: coil    -   12 a, 62 a, 62 aB, 62 aT, 912 a: coil end    -   12 b, 62 b, 62 bB, 62 bT: transition wire    -   13, 63, 63B, 63T, 631, 913: insulator    -   13 a, 63 a: bottom surface part    -   13 b, 63 b: outer peripheral wall    -   13 c, 63 c: inner peripheral wall    -   20, 80, 920: rotor    -   21: rotary shaft    -   21 p: output shaft    -   22, 82: rotation body    -   23, 83: rotor core    -   24, 84: magnet    -   30A, 30B: shaft bearing    -   31, 131, 931: molding resin    -   31 a: barrel    -   31 b: coil end mold    -   32, 35: first bracket    -   33, 65: second bracket    -   34: circuit board    -   34 a: electronic component    -   34 b, 65 b: opening    -   35 a, 65 a: holder    -   36, 365: terminal cap    -   41A, 41B, 41C, 41D, 42A, 42B, 43, 44, 45, 50, 51, 52, 53, 54,        55, 56, 57, 58, 59: non-combustible layer    -   45 a, 45 b, 58 a, 58 b: end part    -   46, 47: metallic cover unit    -   50 a, 51 a, 52 a, 53 a: outer peripheral enclosure    -   50 b, 51 b, 52 b, 53 b: side enclosure    -   50 c, 51 c: inner peripheral enclosure    -   57 a: bulging part    -   61 c: slot    -   61 d, 63 f: protrusion    -   61 ba: tooth middle part    -   61 bb: tooth top end    -   63 d: pin    -   63 e: positioning part    -   64, 641, 644: coil assembly    -   66, 661, 664: metallic inner cover    -   66 a: small-diameter part    -   66 b: large-diameter part    -   68: wire holder    -   69, 692, 696: molding resin part    -   69 a: mounting part    -   69 b: wire hole    -   76, 763, 766: metallic outer cover    -   76 a: top surface    -   76 b: curved surface    -   76 c: cylindrical part    -   76 d, 631 c, 661 c, 692 a 2, 763 d 2: tapered part    -   76 h: opening part    -   76 aa, 76 ca: overlapping part    -   83 a: magnet insertion hole    -   83 b: resin through hole    -   86: rotor resin part    -   86 a: end plate resin part    -   86 b: inner resin part    -   365 a: terminal face    -   365 b: wall    -   664 c: swaged part    -   692 a: notch    -   692 a 1: notch opening    -   696 a: recess    -   763 d, 766 d: edge part    -   763 d 1: chamfered part    -   766 d 1: bent part

1. A motor comprising: a stator including a stator core, and a coilwound on the stator core; a rotor disposed inside the stator, the rotorincluding a rotary shaft extending in a shaft center direction, and arotation body that includes a magnet component, extends in the shaftcenter direction, and is fixed to the rotary shaft; a shaft bearing thatrotatably holds the rotor; and a molding resin covering the stator,wherein the coil includes a coil end protruding from the stator core inthe shaft center direction, and is provided with a non-combustible layercovering the coil end.
 2. The motor according to claim 1, wherein atleast a part of the non-combustible layer is formed to extend in theshaft center direction at a position on an outer peripheral side of thecoil end.
 3. The motor according to claim 1, wherein at least a part ofthe non-combustible layer is formed to extend, in a radial direction, ata position on a side of the coil end opposite to the stator core.
 4. Themotor according to claim 1, wherein the non-combustible layer is formedon an outer surface of the molding resin.
 5. The motor according toclaim 1, wherein the non-combustible layer is formed to cover the coilend from a position on an outer peripheral side of the coil end, from aposition on a side of the coil end opposite to the stator core, and froma position on an inner peripheral side of the coil end.
 6. The motoraccording to claim 1, wherein the non-combustible layer is formed ofair.
 7. The motor according to claim 1, wherein the non-combustiblelayer is formed of a non-combustible material.
 8. The motor according toclaim 1, further comprising a metallic cover provided to cover the coilend through the molding resin.
 9. The motor according to claim 1,wherein the non-combustible layer further covers a transition wire forthe coil.
 10. The motor according to claim 1, further comprising ametallic inner cover made of metal, the metallic inner cover beingdisposed, as the non-combustible layer, to cover a side surface of thestator core, wherein the stator and the metallic inner cover areintegrated by the molding resin.
 11. The motor according to claim 10,wherein, in the stator, the molding resin covers a whole of the statorcore, the coil, and the metallic inner cover except inner peripheralsurfaces of teeth of the stator core.
 12. The motor according to claim10, further comprising, as the non-combustible layer, a metallic outercover made of metal and provided on a surface of the molding resin on anouter side of the stator.
 13. The motor according to claim 12, whereinthe metallic inner cover covers at least an outer periphery of the coilend on a first side, of the stator core, in the shaft center direction,and the metallic outer cover covers at least an outer periphery of thecoil end on a second side, of the stator core, in the shaft centerdirection.
 14. The motor according to claim 13, wherein the metallicinner cover includes a cylindrical shape including a small-diameter partand a large-diameter part whose diameter is larger than a diameter ofthe small-diameter part, and the stator core includes a positioning partprovided on an outer periphery of the stator core.
 15. The motoraccording to claim 13, wherein the metallic inner cover includes acylindrical shape including a small-diameter part and a large-diameterpart whose diameter is larger than a diameter of the small-diameterpart, the stator core includes a protrusion provided on an outerperiphery of the stator core, and the small-diameter part includes atapered part that has an inverse tapered shape and is provided on an endof the small-diameter part.
 16. The motor according to claim 13, whereinthe molding resin has a notch that is provided in the molding resin andpartially overlaps the metallic outer cover.
 17. The motor according toclaim 13, wherein the metallic outer cover includes a chamfer on an edgepart, of the metallic outer cover, on an opening side.
 18. The motoraccording to claim 13, wherein the stator core includes at least oneprotrusion protruding outward on an outer periphery of the stator core,and the metallic inner cover includes a protrusion formed by a swagingprocess on a part, of the metallic inner cover, in contact with theprotrusion.
 19. The motor according to claim 13, further comprising awall that is formed of an insulating material and is provided in a spacewhere the metallic inner cover and the coil end face each other.
 20. Themotor according to claim 13, wherein the metallic outer cover includes abent part that is formed by bending an edge part of the metallic outercover for preventing slipping off, and the molding resin includes arecess formed in the molding resin.